Update ruby 3.4.6 -> 3.4.7. Update gems. Add trivy scanning and ignore unfixable Debian CVEs. Ignore a test fixture key for Capybara

Dockerfile

@@ -8,7 +8,7 @@
 # For a containerized dev environment, see Dev Containers: https://guides.rubyonrails.org/getting_started_with_devcontainer.html
 
 # Make sure RUBY_VERSION matches the Ruby version in .ruby-version
-ARG RUBY_VERSION=3.4.6
+ARG RUBY_VERSION=3.4.8
 FROM docker.io/library/ruby:$RUBY_VERSION-slim AS base
 
 LABEL org.opencontainers.image.source=https://github.com/dkam/clinch
@@ -16,8 +16,9 @@ LABEL org.opencontainers.image.source=https://github.com/dkam/clinch
 # Rails app lives here
 WORKDIR /rails
 
-# Install base packages
+# Install base packages and upgrade to latest security patches
 RUN apt-get update -qq && \
+    apt-get upgrade -y && \
     apt-get install --no-install-recommends -y curl libjemalloc2 libvips sqlite3 && \
     ln -s /usr/lib/$(uname -m)-linux-gnu/libjemalloc.so.2 /usr/local/lib/libjemalloc.so && \
     rm -rf /var/lib/apt/lists /var/cache/apt/archives